Direct3D 11 WorldViewProjection Matrix Transformation Not Working

I have a simple square I'm drawing in 3D space using Direct3D 11 and SlimDX, with the following coordinates (I know it renders)

0,0,0.5
0,0.5,0.5
0.5,0开发者_StackOverflow.5,0.5
0.5,0,0.5

I have a camera class that handles camera movement by applying matrix transformations to the viewmatrix. e.g. Camera.MoveForward(float x) moves the camera forward by x. It also holds the View and Projection matrices. I instantiate them using the following code:

Matrix view = Matrix.LookAtLH(
    new Vector3(0f, 0f, -5f),
    new Vector3(0f, 0f, 0f),
    new Vector3(0f, 1f, 0f));
Matrix projection = Matrix.PerspectiveFovLH(
    (float)Math.PI/2,
    WINDOWWIDTH/WINDOWHEIGHT,
    0.1f,
    110f);

The world matrix is set to the identity matrix.

In my shader code I transform my coordinates using the following code:

PS_IN VS(VS_IN input)
{
    PS_IN output = (PS_IN)0;

    output.pos = mul( input.pos, WorldViewProjection );
    output.col = float4(1,1,1,1);

    return output;
}

Where WorldViewProjection is set in my code using the following:

Matrix worldview = Matrix.Multiply(world, camera.ViewMatrix);    
Matrix worldviewprojection = Matrix.Multiply(worldview, camera.ProjectionMatrix);

I know the camera class's transformations are working as it's old code I wrote for an MDX application which worked fine, however when this runs I see my square, and moving forwards and backwards works just fine, but moving left and right seems to rotate the square around the Y (up) axis instead of translating it, moving up and down has a similar effect, rotating instead about the X (horizontal) axis.

For reference, the camera movement functions:

public void MoveRight(float distance)
{
    position.Z += (float)(Math.Sin(-angle.Y) * -distance);
    position.X += (float)(Math.Cos(-angle.Y) * -distance);
    updateViewMatrix();
}

public void MoveForward(float distance)
{
    position.X += (float)(Math.Sin(-angle.Y) * -distance);
    position.Z += (float)(Math.Cos(-angle.Y) * -distance);
    updateViewMatrix();
}

public void MoveUp(float distance)
{
    position.Y -= distance;
    updateViewMatrix();
}

private void updateViewMatrix()
{
    ViewMatrix = Matrix.Translation(position.X, position.Y, position.Z) * Matrix.RotationY(angle.Y) * Matrix.RotationX(angle.X) * Matrix.RotationZ(angle.Z);
}

The issue may lie in the line:

output.pos = mul( input.pos, WorldViewProjection );

I would change output.pos to be a float4 and then do:

output.pos = mul( float4(input.pos, 1), WorldViewProjection );

Let me know how this works out. If this isn't the problem, I'll take a deeper look at what may be going on.